1. Field of the Invention
The present invention relates to a hair treating composition and more particularly, to a hair treating composition containing a thioglyceryl ether which is excellent in forming hair waves, but which is safe to use and does not possess an offensive odor.
2. Statement of the Prior Art
Heretofore, a variety of mercaptan derivatives have been widely used as the main ingredient in free-radical polymerization controllers, for so-called first agents for cold perm waves, and for cosmetic stabilizers as well as for other uses. However, mercaptan derivatives generally have a very objectionable odor which is a serious drawback when used in consumer products such as treating agents for the modification of hair, e.g., as first agents for forming cold a perm wave. Therefore, there has been and remains a need for mercaptan derivatives which are free of unpleasant odors.
The most common mercaptan derivatives currently being used for cold waving include thioglycolic acid or salts thereof, or cysteine or salts thereof. However, although thioglycolic acid and their salts exhibit excellent sensitivity their strong mercapto odor is quite objectionable even though their hair waving effect is very good. Therefore, attempts have been made to minimize their odor by deodorization treatment through distillation or by admixing with a high masking fragrance. Unfortunately, these techniques have proven to be inadequate. On the other hand, cysteine or salts thereof possess relatively less mercapto and less sensitivity, but are not desirable in that their hair waving ability is insufficient.
The present inventors have previously found that thioglyceryl alkyl ethers and thioglyceryl phenyl ether exhibit an excellent wave-forming effect, are safe and possess minimal objectionable odor (Japanese Patent Application No. 62-20512). However, these compounds still smell bad as compared to conventional thioglycolic acid or salts and their sensitivity is extremely weak.